/// <summary>
/// Samples student-t distributed random variables.
/// </summary>
/// <remarks>The algorithm is method 2 in section 5, chapter 9
/// in L. Devroye's "Non-Uniform Random Variate Generation"</remarks>
/// <param name="rnd">The random number generator to use.</param>
/// <param name="location">The location (μ) of the distribution.</param>
/// <param name="scale">The scale (σ) of the distribution. Range: σ > 0.</param>
/// <param name="freedom">The degrees of freedom (ν) for the distribution. Range: ν > 0.</param>
/// <returns>a random number from the standard student-t distribution.</returns>
static double SampleUnchecked(System.Random rnd, double location, double scale, double freedom)
{
var gamma = Gamma.SampleUnchecked(rnd, 0.5 * freedom, 0.5);
return(Normal.Sample(rnd, location, scale * System.Math.Sqrt(freedom / gamma)));
}
